In OS X Lion, Apple removed Software Update from the Applications folder, so it doesn’t show up in Launchpad. I wanted to see it in Launchpad so this is what I did: Go to the Finder and then double click on hard drive (such as “Macintosh HD”) and then go to System>Library>Core Services. Find the Software Update application and drag it on top of the Launchpad icon in your Dock. Voila! Done!
When you click on Software Update in Launchpad, it will automatically come up with the window which says it is checking for updates. It should act normally. So then, I don’t need to go to the Apple menu and select Software Update anymore.
P.S. This tutorial may sound kinda crazy to you.